iPhone 6s wifi issues

ever since I updated to the iOS 9 and then the 9.2 my phone doesn't pick up the wifi networks and won't stay connected when it does. Before the system update the phone stayed connected to xfinitywifi without a problem. I have tried the hard restart of the phone, resetting the network settings to factory settings, and am becoming extremely frustrated with this. I have a galaxy s5 as well and it picks up the wifi networks no problem and the cellular signal is full whereas my iPhone gets crap signal with only 2 dots filled in. I am ready to return the iPhone and go back to android if no solution to this problem as I find it ridiculous that you pay 700 plus dollars for a phone and it doesn't stay connected or even pickup wifi connections When I know there should be ones showing. Has anyone else experienced this? And does anyone know how to fix? Thanks in advance.